District 5 to experiment with salt-only
treatment on several highway segments

ITD crews in the Montpelier, Preston and Malad areas
will use a different method of winter maintenance on selected highways
entering from Utah and Wyoming this winter.

Depending on the prevailing weather conditions and temperature,
salt may be used exclusively or combined with small amounts of sanding
material. Routes targeted for the new treatment include Interstate 15
from the Idaho/Utah line to Malad, U.S. 91 from the state line to Preston,
U.S. 89 from the state line to Montpelier, and U.S. 30 from the Idaho/Wyoming
state line to Montpelier.

ITD's use of salt on those segments will mirror the approach
Utah uses to clear snow accumulations so motorists traveling from Utah
will not experience a radical change when they reach the state line,
explains Steve Gertonson, ITD District 5 maintenance engineer. Utah
has experienced good success with salt-only applications for many years.

Recent tests in northern Idaho also proved effective
in the treatment of highways that receive regular winter snowfalls.

Crews don't immediately begin snow removal from the highways
in Utah. Instead, once the snow depths reach 3-5 inches, trucks apply
salt to begin melting the accumulation; when snow turns to slush, plows
push it from the highway. The remaining salt/water solution on the highway
surface also helps prevent ice build-up and should eliminate conditions
called "broken snow floor" where patches of packed snow remain
after plowing.

Instead of placing a salt/sand mixture several times
during a storm, the concept is to put an initial, heavier application
of salt at the beginning of a storm, thus lowering the freezing point
on the road surface and preventing accumulation, Gertonson explains.

The difference regular drivers on Idaho's experimental
segments will notice is that snow removal will not begin immediately
when a storm arrives. They should anticipate small accumulations before
treatment and should drive accordingly, Gertonson says.

The experimental salt application and slush removal should
result in personnel, equipment and fuel savings.

"We anticipate this test use of salt only will result
in a number of important benefits," Gertonson says. "The most
important result should be improved safety for motorists."

Increased use of salt also should make spring cleanups
easier and less costly than the removal of more traditional sanding
materials. It also should reduce the risk of windshield breakage from
sand and gravel and improve the environment by adding fewer particulates
into the air.

ITD crews will will continue to treat highways outside
the trial segments as they have in the past.

Soil samples have been taken along each selected route
to monitor chloride levels and help protect the environment, but Gertonson
expects no adverse impact. The amount of straight salt applied to highways
should be about the same as with repeated salt-sand applications.

Motorists who drive through an area that has been treated
with salt only should wash their vehicles often to prevent salt accumulations
and minimize corrosion.